The PES beads formed via phase inversion route were found to
be spherical shaped with diameter of ~2.5 mm. Fig 5a highlights the
SEM image of the cross sectional segment of control PES bead
(magnification ¼ 300). The image suggests that PES beads formed
via phase inversion process have porous leaf like structures
comprising of random channels. The porous structure was formed
due to the diffusion of NMP from the inner core of the beads towards
the periphery. The bulk morphology of the PES beads